/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j.helpers;

import java.io.Writer;
import java.io.FilterWriter;
import java.io.IOException;
import org.apache.log4j.spi.ErrorHandler;
import org.apache.log4j.spi.ErrorCode;

/**
 * QuietWriter does not throw exceptions when things go wrong. Instead, it
 * delegates error handling to its {@link ErrorHandler}.
 * 
 * @author Ceki G&uuml;lc&uuml;
 * @since 0.7.3
 */
public class QuietWriter extends FilterWriter {

	protected ErrorHandler errorHandler;

	public QuietWriter(Writer writer, ErrorHandler errorHandler) {
		super(writer);
		setErrorHandler(errorHandler);
	}

	public void write(String string) {
		try {
			out.write(string);
		} catch (IOException e) {
			errorHandler.error("Failed to write [" + string + "].", e,
					ErrorCode.WRITE_FAILURE);
		}
	}

	public void flush() {
		try {
			out.flush();
		} catch (IOException e) {
			errorHandler.error("Failed to flush writer,", e,
					ErrorCode.FLUSH_FAILURE);
		}
	}

	public void setErrorHandler(ErrorHandler eh) {
		if (eh == null) {
			// This is a programming error on the part of the enclosing
			// appender.
			throw new IllegalArgumentException(
					"Attempted to set null ErrorHandler.");
		} else {
			this.errorHandler = eh;
		}
	}
}
